This invention relates, in general, to a process for producing ground flavoring materials which are readily dispersible in aqueous solution. More particularly, the invention relates to a process for producing a mustard seed powder finer than about 70 mesh and capable of forming an aqueous dispersion substantially free of agglomerated particles.
The production of finely divided flavoring materials, on the order of about 70 mesh or finer, is at present a relatively inefficient and cumbersome procedure. This is due primarily to the difficulty of grinding a material, such as mustard seed, which is not in a dry and pulverulent condition, but rather, contains oils and fats which are partially released during comminution, making it extremely difficult to grind the resulting pasty substance. The problem of oil release becomes increasingly troublesome depending upon the extent of comminution. Thus, the quantity of oil released when attempting to grind the mustard seed to a particle size finer than about 70 mesh is frequently sufficient to bring the entire grinding operation to a halt because the released oil converts the finely divided mustard powder into a gumlike material which is practically impossible to pulverize.
One of the key objectives in mustard seed grinding operations is to produce particles sufficiently fine to be suitable for high-grade mustard preparations which form the basis of salad dressings and mayonnaise. This requires a particle size finer than about 70 mesh to insure that the finished product has the desired smoothness and clarity. particles coarser than 70 mesh are generally restricted to the so-called low-grade mustard preparations in which the effect of particle size on the products visual appeal is relatively unimportant.
Conventional processes for comminuting mustard seed comprise an initial aging step wherein the seed is aged from about 6-18 months to facilitate removal of hulls from the seed. This is followed by a dehulling operation in which the aged seeds are passed through a roll mill. The dehulled seeds are then pulverized using conventional milling techniques to produce a product approximately 70% of which is finer than 70 mesh (the desired particle size); the remaining 30% comprises the oversized material and represents the major source of inefficiency in the overall process.
In an attempt to improve the efficiency of grinding oily spices and flavoring materials cryogenic comminution processes have been suggested in the art. U.S. Pat. No. 3,314,802 to Cohodas, for example, discloses a cryogenic process for grinding mustard seed to a particle size of 30 mesh, while U.S. Pat. No. 2,583,697 to Hendry et al discloses a comminution process wherein cacao beans, cocoanut meat and spices such as cloves, nutmeg and pepper (not including mustard) may be ground to extremely fine particle sizes in a hammermill at a temperature of about -200.degree.F. However, these patents fail to address themselves to the problem of producing mustard seed powder capable of being used in highgrade mustard preparations. That is, the cryogenic grinding processes known in the art are either incapable of producing a powder having the requisite particle size (i.e. 70 mesh or finer) or else they fail to produce a powder capable of forming a water dispersion free of agglomerated particles, namely, a powder suitable for use in preparing foodstuffs such as salad dressings and/or mayonnaise. Accordingly, the process of Cohodas results in a relatively coarse mustard seed powder suitable only for low-grade mustard preparations. The process of Hendry et al, on the other hand, although presumably not intended for the grinding of mustard seed, nevertheless, is capable of producing mustard seed particles finer than 70 mesh. However, such powder if added to water would form "clumps" or particles of agglomerated mustard, thereby rendering the process virtually useless insofar as high-grade mustard preparations are concerned.